Conventional prior art mass market computing platforms include the well-known personal computer (PC) and competing products such as the Apple Macintosh™, and a proliferation of known palm-top and laptop personal computers. Generally, markets for such machines fall into two categories, these being domestic or consumer, and corporate. A general requirement for a computing platform for domestic or consumer use is a relatively high processing power, Internet access features, and multi-media features for handling computer games. For this type of computing platform, the Microsoft Windows® '95 and '98 operating system products and Intel processors dominate the market.
On the other hand, for business use, there are a plethora of available proprietary computer platform solutions available aimed at organizations ranging from small businesses to multi-national organizations. In many of these applications, a server platform provides centralized data storage, and application functionality for a plurality of client stations. For business use, other key criteria are reliability, networking features, and security features. For such platforms, the Microsoft Windows NT 4.0™ operating system is common, as well as the Unix™ operating system.
With the increase in commercial activity transacted over the Internet, known as “e-commerce”, there has been much interest in the prior art on enabling data transactions between computing platforms, over the Internet. However, because of the potential for fraud and manipulation of electronic data, in such proposals, fully automated transactions with distant unknown parties on a wide-spread scale as required for a fully transparent and efficient market place have so far been held back. The fundamental issue is one of trust between interacting computer platforms for the making of such transactions.
There have been several prior art schemes which are aimed at increasing the security and trustworthiness of computer platforms. Predominantly, these rely upon adding in security features at the application level, that is to say the security features are not inherently imbedded in the kernel of operating systems, and are not built in to the fundamental hardware components of the computing platform. Portable computer devices have already appeared on the market which include a smart card, which contains data specific to a user, which is input into a smart card reader on the computer. Presently, such smart cards are at the level of being add-on extras to conventional personal computers, and in some cases are integrated into a casing of a known computer. Although these prior art schemes go some way to improving the security of computer platforms, the levels of security and trustworthiness gained by prior art schemes may be considered insufficient to enable widespread application of automated transactions between computer platforms. Before businesses expose significant value transactions to electronic commerce on a widespread scale, they may require greater confidence in the trustworthiness of the underlying technology.
In the applicant's co-pending International Patent Applications ‘Trusted Computing Platform’ PCT/GB 00/00528, filed on 15 Feb. 2000, and ‘Smartcard User Interface for Trusted Computing Platform’ PCT/GB 00/00752, filed on 3 Mar. 2000, the entire contents of which are incorporated herein by reference, there is disclosed a concept of a ‘trusted computing platform’ comprising a computing platform which has a ‘trusted component’ in the form of a built-in hardware and software component. Two computing entities each provisioned with such a trusted component, may interact with each other with a high degree of ‘trust’. That is to say, where the first and second computing entities interact with each other the security of the interaction is enhanced compared to the case where no trusted component is present, because                A user of a computing entity has higher confidence in the integrity and security of his/her own computer entity and in the integrity and security of the computer entity belonging to the other computing entity.        Each entity is confident that the other entity is in fact the entity which it purports to be;        Where one or both of the entities represent a party to a transaction, e.g. a data transfer transaction, because of the in-built trusted component, third party entities interacting with the entity have a high degree of confidence that the entity does in fact represent such a party        The trusted component increases the inherent security of the entity itself, through verification and monitoring processes implemented by the trusted component.        The computer entity is more likely to behave in the way it is expected to behave.        
Prior art computing platforms have several problems which need to be overcome in order to realize the potential of the applicants' above disclosed trusted component concept. In particular,                The operating status of a computer system or platform and the status of the data within the platform or system is dynamic and difficult to predict. It is difficult to determine whether a computer platform is operating correctly because the state of the computer platform and data on the platform is constantly changing and the computer platform itself may be dynamically changing.        From a security point of view, commercial computer platforms, in particular client platforms, are often deployed in environments which are vulnerable to unauthorized modification. The main areas of vulnerability include modification by software loaded by a user, or by software loaded via a network connection. Particularly, but not exclusively, conventional computer platforms may be vulnerable to attack by virus programs, with varying degrees of hostility.        Computer platforms may be upgraded or their capabilities extended or restricted by physical modification, i.e. addition or deletion of components such as hard disk drives, peripheral drivers and the like.        
In particular, conventional computer platforms are susceptible to attack by computer viruses, of which there are thousands of different varieties. Several proprietary virus finding and correcting applications are known, for example the Dr Solomons™ virus toolkit program, and the Microsoft™ virus guard facility provided within the Windows™ operating system. However, such virus packages protect primarily against known viruses, and new strains of virus are being developed and released into the computing and internet environment on an ongoing basis.